Negative-resistance repeater.



H. DE F. ARNOLD. NEGATIVE RESISTANCE REPEATER.

APPLICATION FILED MAY 7, 1914.

Affj/ Patentea Nov. 24, 1914.

peating apparatus, and particularly-to the um'rnn STATES PAT? HAROLD DE FOREST ARNOLD, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, OF NEW YORK, N. Y., A GORPORATION'OF ILLINOIS.

NEGATIVE-RESISTANCE nnrna'rna.

Specification 01' Letters Patent.

Patented Nov. 24, 191 3:.

Application filed May 7, 1914. Serial No. 837,045;

To all whom it may concern:

Be it knownthat I, HAROLD Dn Foeus'r 'ARNOLD, a citizen of the United States, re-

'ed a certain new and useful Improvement in Negative-Resistance Repeaters, of which the following is a full, clear, concise, and exact description.

This invention relates to electric wave reuse of a negative resistance for repeating and amplifying waves of electric energy.

Its objects are to secure, in a simplified form of apparatus, amplified reproductions of variations of current energy without distortion of wave form.

The invention is applicable, among other uses, to telephony for the purpose of obtaining in an outgoing circuit an amplification of voice currents originating in an incc-ming circuit. It is also applicable to telegraphy and signaling systems in general, where amplification is necessary in receiving, recording or reproducing impulses of electrical energy. 1 1

In carrying out the invention use is made of the principle of negative resistance, that is, a resistance having the characteristic of adding energy to an alternating currentcircuit of which it forms a part, 0r in other words, the characteristic of increasing current for decreasing potential across the terminals. I

The present invention is based on the discovery that an enormously highnegative resistance may exist across a pair of auxiliary electrodes located at opposite sides of an ionized column of vapor.

The invention will be more fully-understood by reference to the accompanying drawings, wherein--- Figure lshows a system of circuits and apparatus by which the invention may be carried out; and Fig. 2 shows a .modified form of circuits and apparatus likewise embodying the invention.

Referring to the drawings, the means for producing an ionized column of vapor preferably consists of a mercury arc apparatus, comprising an evacuated vessel 1 having therein a mercury cathode 2 and an anode 3 of any suitable material. It will be understood that any suitable means, not shown,

may be employed for starting the are between the anode and cathode.

Supported within the vessel 1 are apair of auxiliary electrodes 1, 5, arranged at opposite sides of thevapor column, and preferably disposed exactly opposite each other. By such arrangement ionized mercury vapor is maintained between said auxiliary electrodes. Leading-in conductors, of platinumwire or. other suitable material, are provided for the several electrodes of the device.

Both in Figs. 1 and 2 a two-way transmission system is shown, the two halves of, the system being alike. Either half may, therefore, be considered at the input circuit, and the other half the outputcircuit.

Suitable means are provided for impressing negative potential on both of the electrodes 4 and 5. In the circuit arrangement shown, such means comprises a battery 6 or other suitable source of continuous current. The negative pole ofsaid battery 6 is connected to each of the auxiliary electrodes 4 and 5, and the positive pole thereof may be connected to one of the electrodes 2 and 3, it being shown in the drawings as connected to the anode 3. For convenience of illustration, the battery 6 is shown as the same battery that is employed for supplying the current that produces the mercury vapor stream between the cathode 2 and the anode 3, but it "will be understood that the use of a common battery is not necessary. The negativepotential of the auxiliary electrodes 4 and 5 is much higher than the negative potential of the cathode 2. For example, the negative otential of the auxiliary electrodes shou d preferably be forty volts or more higher than the negative potential of the cathode.

In Fig. 1 circuits, which include the auxiliary electrodes 4 and 5, may be traced as follows :'from the negative pole of the battery 6, through the conductor 7 over the parallel branches 8 and 9, to the electrodes 4 and 5, and from thence to the anode 3, which is connected to the positive pole of the battery. Each of the branches-8 and 9 includes a coil 10 and 11, respectively, of a transformer 13 and 14, of which 15 and 1,6.

are the other coils- A circuit may also be traced from one of said auxiliary electrodes 11 in series. In this circuit arrangement the branch 8, which includes the coil 10, may be considered as, the input circuit, and the branch 9, which includes the coil 11, may be considered as the output circuit, or vice versa. One or the other of the coils 10 and 11 may thus be considered as a source of fluctuating current. It will thus be seen that means are provided for impressing a fluctuating current upon the direct current flow from the battery 6. Owing to the high negative resistance across the electrodes 4: and 5, the current flow produced by the fluctuating current in the input circuit is greatly amplified, and such amplification is repeated in the output circuit.

In Fig. Ban arrangement is shown for producing substantially the same results as are obtained from the arrangement shown in Fig. 1. In said Fig. 2 the negative pole of the battery 6 is shown as connected with the auxiliary electrodes 4 and 5, respectively, by the two parallel branches 18 and 19. The branches 18 and 19 include the retardation coils 20 and 21, respectively. In said Fig. 2,

the coils 10 or 11 may provide means for im- 1 pressing a fluctuating current upon the con tinuousv current in the portion of the circuit included between the electrodes 1 and 5.

The circuit for producing the mercury vapor are between the anode and cathode includes thecustomary resistance and high impedance 24. i It has heretofore been recognized that the main arc stream between the cathode 2 and the anode 3 can be used as a negative resistance repeater. In such case. however, the negative resistance has been found to be approximately'but two ohms as compared with the negative resistance of approximately four hundred thousand (400,000) ohms between the auxiliary electrodes. 'Ihis enormous diflerence indicates that the present invention is based upon a difl'erent' principle from that heretofore employed.

What is claimed is:

1. In a repeater, the combination with a vessel and means for maintaining a state of ionization in said vessel; of a circuit including a pair of electrodes disposed within said vessel at opposite sides of the ionized space; means for impressing negative potential upon said electrodes; and a source of fluctuating current in said circuit.

2. In a repeater, the combination with a vessel and means including a cathode and an anode for maintaining a state of ionization in said vessel; of a pair of auxiliary electrodes disposed within said vessel at opposite sides thereof, a circuit including a source 0t ensure continuous current having its negative pole connected in parallel to each of said auxi1- iary electrodes, and a source of fluctuating current having a circuit including said auxiliary electrodes.

3. In a repeater, the combination with a vessel and means including a cathode and an anode for maintaining a column of ionized vapor in said vessel between said cathode and anode; of a pair of auxiliary electrodes at opposite sides of said column of ionized vapor, and a circuit including a source of continuous current having its negative pole cdnnected to each of said auxiliary electrodes, said circuit also including a source of fluctuating current.

4. In a repeater, the combination with a vessel and means including a cathode and an anode for maintaining a column of ionized vapor in said vessel between said cathode and anode; of a pair of auxiliary electrodes at approximately equal distances from said cathode; a circuit including a source of pontinuous current having its negative pole connected in parallel to each of said auxiliary electrodes, said circuit including a portion of said column of ionized vapor but excluding that portion thereof adjacent said oath ode; and means for impressing a fluctuating current upon said continuous current.

5. In a repeater the combination with a vessel, a cathode and an anode therein, and means for maintaining ionized vapor in said vessel between said cathode and anode; of a pair of auxiliary electrodes in said vessel; and input and output circuits connected to said auxiliary electrodes respectively and in eluding in common a source of continuous current.

6. In a repeater the combination with a vessel, a cathode and an anode therein, and means for maintaining an ionized vapor in said vessel between said cathode and anode, said means including a source of continuous current; of a pair of auxiliary electrodes in said vessel at opposite sides thereof, and input and output circuits connected to said auxiliary electrodes respectively and including in common said source of continuous current.

7. In a repeating system, the combination with a vessel, of means for maintaining a state of ionization in said vessel, means for maintaining a negative potential upon. opposite sides of the ionized space, andunput and output circuits connected with said potential maintaining means;

In witness whereof I hereunto subscribe my name this 4 day oi May A. D., 1914:.

HARULD DE FOREST ARNOLD.

Witnesses:

KATHERINE L. STAHL, NANON E. 'lnTnrLL. 

